Significant reduction of indeterminate (atypical) diagnosis after implementation of The Paris System for Reporting Urinary Cytology: A single‐institution study of more than 27,000 cases

Abstract

Background Urinary cytology is a noninvasive and cost‐effective diagnostic and surveillance test in the clinical management of urothelial carcinoma (UC). The Paris System for Reporting Urinary Cytology (TPS), published in 2016, introduced definite diagnostic criteria aimed at improving performance in detecting high‐grade UC (HGUC) and decreasing the indeterminate (atypical) diagnosis. Methods The authors retrospectively reviewed and compared urinary cytology diagnoses reported between January 2013 and December 2014 (pre‐TPS, 7658 cases) and between May 2016 and April 2018 (post‐TPS, 20,026 cases) to assess the influence of TPS in their practice. The time in between was used as a learning period. Follow‐up information and correlation with the UroVysion fluorescence in situ hybridization test were obtained when available. Results Urinary cytology diagnoses pre‐TPS included negative for UC (NUC) (n = 5293; 69.2%), atypical urothelial cells (AUC) (n = 2227; 29%), and suspicious/positive for HGUC (SHGUC/HGUC) (n = 138; 1.8%). Diagnoses post‐TPS included negative for HGUC (NHGUC) (n = 18,507; 92.4%), AUC (n = 1237; 6.2%), and SHGUC/HGUC (n = 282; 1.4%). Comparing the pre‐TPS and post‐TPS periods, AUC diagnoses decreased from 29% to 6.2% (P < .00001), and the specificity and positive predictive value of AUC to detect HGUC significantly improved from 49% to 86% (P < .00001) and from 9% to 39% (P = .002), respectively. The correlation of an AUC diagnosis with a positive UroVysion test improved from 17% to 38% (P < .00001), whereas overall use of the UroVysion test was decreased. Conclusions Implementation of TPS resulted in a significant reduction in AUC diagnoses that had a superior correlation with a subsequent biopsy and a UroVysion test, resulting in potential reductions in test use and medical cost.

Atypical urothelial cells classified according to the Paris System for Reporting Urinary Cytology: A 2‐year experience with histological correlation from a Finnish tertiary care center—low rate and high risk of malignancy

“…The overall figures decreased from 18.6% to 14.4% and in voided urine the decrease in AUC diagnoses was from 20% to 14.5%. 19 Still, other studies have shown a decrease in AUC diagnoses in both instrumented (36.6% to 9.1%) and voided (26.9% to 6.0%) urine samples, 20 although instrumented samples had a higher AUC rate. According to some authors, instrumentation artifacts may enhance nuclear border irregularities and 10 Cowan et al 4 reported the post-TPS ROM in the AUC category as 7%-53% in comparison to the pre-TPS range of 28.3%-33%.…”

UroVysion fluorescence in situ hybridization in urothelial carcinoma: a narrative review and future perspectives

“…Recently, Tian et al (2020) chronologically reviewed and retrospectively compared urine cytology diagnoses between pre-TPS and post-TPS, and described that all categories in urine cytology had superior correlation with UroVysion results by post-TPS, and positive UroVysion results increased from 87% to 93% in suspicious for HGUC category. By these results, it is hopeful that application of TPS could lead to significant reduction of atypical UC diagnosis, and potential cost effectiveness (60).…”

The Paris System for Reporting Urinary Cytology: A Meta-Analysis

“…From its implementation, it has been shown to enhance correlation with histology, especially when the low urinary tract is sampled, while decreasing the indeterminate diagnoses [46,47]. Indeed, a few studies have demonstrated that TPS has reduced the rate of atypical interpretations reported in their departments [48][49][50][51]. This finding has a great clinical significance, as before the implementation of TPS, many urologists were regarding atypical cases as negative [6].…”

“…Nevertheless, TPS focuses on what is more important, which is the detection of HGUC [1,7]. Thus, it has established strict criteria for each one of its categories, including AUC, aiming to identify HGUC rather than LGUN, resulting in a frequency reduction in the "atypical" interpretations compared to the pre-TPS era [48][49][50][51]. Of interest, the pooled ROHM of the AUC reporting category in our meta-analysis was found to be 38.65% (95% CI, 0.3042; 0.4759), which should warrant close clinical follow-up and/or the use of ancillary testing [1,7], rather than being regarded as negative.…”